The watch over water.

During the Cold War the development of the principal maritime patrol aircraft (MPA) was driven by the need to find and attack nuclear-powered submarines deep in the middle of the ocean. On a global scale, anti-submarine warfare (ASW) is now less dominant, although diesel-electric submarines are proliferating. The maritime patrol aircraft is typically tasked with a broad range of blue water and littoral missions, including anti-surface vessel warfare (ASuW), fisheries-protection, search-and-rescue, and anti-pollution patrols.

Any survey of recent developments in the maritime patrol aircraft field is complicated by the ease with which a useful over-water surveillance system can be produced by equipping any small commercial twin-turboprop aircraft with a lightweight radar, an electro-optical/infrared (EO/IR) turret and appropriate monitors. There are many such aircraft grossing between five and 25 tonnes, and the maritime patrol aircraft range is growing steadily as littoral nations attempt to monitor activities in their 370 km exclusive economic zones (EEZ).

The twin-turboprop maritime patrol aircraft is illustrated by the Eads-Casa series, ranging from the 8.1-tonne C-212 through the 15.8-tonne CN-235 and to the new 23.2-tonne C-295. MPA variants of all these transports have been developed, and they are now offered with the company's own Fully-Integrated Tactical System (Fits), which has also been applied to Spain's Lockheed Martin P-3Bs. The Fits-equipped CN-235-300 Persuader has been selected by the US Coast Guard, with 35 aircraft required. The United Arab Emirates has selected the C-295, equipped with a Raytheon SeaVue radar and Flir Systems Star Safire II E-O turret.

Platforms competing with the CN-235 and C-295 are the 18.1-tonne Bombardier Dash 8, the 18.6-tonne ATR400MP Surveyor and the 22.5-tonne ATR72 ASW. Future possibilities include maritime patrol aircraft versions of the 12.5-tonne Sukhoi S-80, 20-tonne Ilyushin Il-214, 23.5-tonne Il-114, 27-tonne Antonov An-32, China's 21.8-tonne Xian MA-60 (An-26 derivative), and the 31.8-tonne Lockheed Martin/Alenia C-27J.

Turning to twin-jet aircraft, a number of maritime patrol aircraft have been derived from business jets, as exemplified by the 18-tonne Dassault Falcon 50M. Regional transports have served in the same way, as illustrated by the 32-tonne Antonov An-72P. One of the most remarkable developments of recent years has been the way in which Embraer has produced a family of advanced special mission aircraft on the basis of the 22-tonne ERJ-145. The latest example is the P 99 MPA, with a 360-degree ventral radar, two underwing hardpoints for 900 kg stores and three or more operator stations in the cabin. The P 99 proposed for Brazil has a Thales Amascos mission system, including Ocean Master radar and Agile flir. Options include a flight-refuelling probe. The P 99B is designed for MP and ASuW roles, providing a strike radius of 1675 km. The P 99C combines the MP and ASW roles, and provides over four hours on station at a low level and a radius of 370 km.

Historically, flying boats have played a major role in maritime patrol, but the trend is toward amphibians, exemplified by the 17-tonne Bombardier CL-415, the 31-tonne Beriev Be-12 and the 43-tonne Shin Maywa US-1A, the Kai version of which will have Rolls-Royce AE2100J engines. One with considerable potential as a maritime patrol aircraft (especially in search-and-rescue) is the 37.2-tonne Beriev Be-200ChS being produced by NPK Irkut (recently merged with Yakovlev) for the Russian Ministry of Emergency Situations. Irkut, Eads and Rolls-Royce Deutschland are collaborating on a Westernised Be-200 with BR715 turbofans (the Irkut works, it may be added here, were originally named Irkutsk after the Siberian capital where they are located; they were renamed Irkut purely for pronunciation reasons). Beriev's amphibian developments include the 86-tonne A-40: an order for 20 for the Russian Navy has been stalled by funding problems.

Orion

The 61-tonne Lockheed Martin P-3 Orion is still the world's principal maritime patrol aircraft. Whereas the Lockheed P-2 Neptune that it replaced had a belly-mounted radome for 360-degree cover, the P-3 brought the innovation of twin antennas mounted in the nose and rear fuselage. Powered by four Allison (now Rolls-Royce) T56 turboprops, the P-3A entered service in 1962. Including 100 built by Kawasaki, 751 P-3s have been completed, of which 345 were P-3Cs. The final P-3C Update III for the US Navy was delivered in 1990, and the last export example constructed in America flew in 1995.

The US Navy has about 228 P-3Cs in service as well as small numbers of special mission variants, notably the electronic warfare EP-3. The Orion also serves Argentina, Australia, Brazil, Canada, Chile, Greece, Iran, Japan, the Netherlands, New Zealand, Norway, Pakistan, Portugal, South Korea, Spain and Thailand. The Netherlands is about to dispose of its P-3Cs as a cost-cutting measure, but this move may well add Germany to the list of operators. India is negotiating to buy eight P-3Cs with an option on ten more, but may be dissuaded by the strings attached. This deal would presumably lead to cancellation of the Ilyushin Il-38 upgrade (discussed later).

Orions have gone through a series of upgrade programmes. In the case of the US Navy, the two most recent modernisation efforts have been the Block Modification Upgrade Program, which takes all P-3Cs to Update III standard, and the Anti-Surface Warfare Improvement Program (AIP). The AIP includes clearance for the Raytheon AGM-65F Maverick and Boeing AGM-84E Slam-ER, and introduction of the Raytheon APS-137B(V)5 radar; the only production sensor with both multi-resolution SAR (synthetic aperture radar) and Isar (inverse Sar) modes.

Plans to give 200 US Navy P-3Cs a service life extension programme (Slep) were officially abandoned in favour of acquiring new-build Multi-mission Maritime Aircraft (MMA), although a rewing programme still appears likely. The MMA was originally to replace the Sigint EP-3, but last February it was decided to treat the latter separately. It is planned to launch MMA low-rate initial production in 2009 and have the first MMA squadron in service by 2012. There were initially to have been 300 MMAs, but this total has been reduced in steps to between 130 and 150, and some sources now quote 108.

The component advanced development phase began in September 2002, with contracts awarded to Boeing and Lockheed Martin. The phase is a risk-reduction and design refinement effort, leading to a single-contractor four-year system development and demonstration phase, which will include the construction and testing of three flying and two ground test aircraft. The final request for proposals was due to be released in mid-September 2003, leading to submissions in mid-November and down-selection in March/April 2004. First flight is expected in 2008-2009.

The US Navy reportedly now believes that at least 40 per cent of the tasks originally assigned to the MMA can be performed by drones. It is therefore anticipated that the MMA will be operated in conjunction with the Broad Area Maritime Surveillance (Bams) drone, which will collect electronic and signals intelligence and send it back to the area commander. It will also relay signals between aircraft and ships. The funding for Bams procurement is due to begin in FY2007, and a fleet of around 50 is planned. The swing toward using drones for high altitude duties reflects increased emphasis on low level ASW operations by the manned aircraft, which arguably favours the use of turboprops rather than turbofans.

The obvious Bams contenders are the Northrop Grumman RQ-4A Global Hawk and the General Atomics Predator B-ER, the latter (on which Lockheed Martin is teamed with General Atomics) uses the long-span wing from the company's Nasa Altair. However, Gulfstream Aerospace has recently proposed an RQ-37 unmanned version of the G550 business jet (formerly the GV-SP, which first flew in August 2001). Given its background, the RQ-37 could provide a significantly lower attrition rate than existing unmanned aerial vehicles, combined with several times the payload and much more electrical power. Although much heavier by far than an RQ-4A, a 'green' RQ-37 would not be correspondingly more expensive and there may be little percentage difference between the two when equipped to the same standard. The first four Bams are due to join the fleet in 2009.

The US Navy also wants a much smaller vertical take-off UAV (VTUAV) to operate from ships other than aircraft carriers, providing tactical reconnaissance and communications relay facilities. The VTUAV could eventuate as a derivative of the Northrop Grumman Sea Scout (one version of which has been selected for the US Army Class IV UAV for its Boeing-led Future Combat System), or a variant of the US Coast Guard's Bell Eagle Eye tilt-rotor vehicle, of which 69 examples are expected to be purchased by that service. Talking of the Fire Scout, Northrop Grumman is now introducing a four bladed version of the rotorcraft, which gives it a 272 kg lift capacity.

The relatively large Barns is to be augmented by an US Navy Ucav, based on either the Boeing X-45 or Northrop Grumman X-47, both of which are Darpa-funded. The carrier-operated Ucav is scheduled to enter service in the reconnaissance role in 2015, and in the strike role around 2020 (an article on dedicated naval Ucavs and drones will appear in the next issue of Armada).

In May 2003, the US Navy opened the MMA and Bams programmes to international participation, inviting financial contributions from Australia, Canada, Germany, Italy, Japan, Norway, the Netherlands, Portugal, South Korea and Spain. However, unlike the Lockheed Martin F-35 programme, which pioneered the concept of other governments subsidising American military equipment developments, the MMA operational requirements are too far advanced for foreign needs to have any impact. In addition, the F-35 programme has left several contributors with a bitter taste due to lack of associated work, a situation that is hardly helped by the present Congressional mood to strengthen its 'Buy American' policy

The only other major non-American players in the maritime patrol aircraft field are the United Kingdom and Japan. The former is already committed to the BAE Systems Nimrod MRA4, while the latter is developing the Kawasaki P-X (both aircraft are discussed later).

MMA

Details of the MMA need statement are still classified, but emphasis has now been placed on an anti-submarine warfare mission, reportedly involving three hours on station at 2000 ft and within a radius of 2200 km, followed by 30 minutes at 500 ft. Warload is given as at least 4500 kg (compared to the 8730 kg maximum of the P-3C), including two Mk 50 torpedoes, four 225 kg depth charges and 80 sonobouys.

From developmental cost, risk and timescale standpoints, the front-runner in the MMA contest is presumably Lockheed Martin, proposing what might be described as a new-generation Orion and benefiting from its vast background experience. However, the company accepts that it will have to use its experience with other programmes to propose an innovative approach to reducing maintenance costs.

The Lockheed Martin MMA airframe would retain the existing external shape but would take advantage of modern aluminium alloys and manufacturing techniques. All suitable turboprops have been studied, but the smart money may be on the Rolls-Royce AE2100, as used in the Lockheed Martin C-130J and LM/Alenia C-27J. Lockheed Martin is proposing a new 'all-glass' cockpit by Rockwell Collins and an autopilot by BAE Systems. The current APS-137B(V)5 radar may be retained, but consideration has also been given to AESA (Active Electronically-Scanned Array) radars proposed by Northrop Grumman and Raytheon.

Since there will be at least 20 years of overlap between the P-3C and MMA in US Navy service, it would be highly advantageous if some structural components developed for the MMA are retrofittable to existing P-3Cs. It is noteworthy that Lockheed Martin has already placed a contract with Vought to design and develop a new wing for the P-3C, which would also serve for the MMA. Lockheed Martin (if selected for the MMA) will thus be able to offer foreign customers a range of options, from a Slep package for existing P-3s to a new-build MMA.

The Boeing MMA proposal was initially based on the 77.5-tonne 737-700IGW (Navy designation C-40A), but last March the service changed the requirement, forcing a switch to the 82.5-tonne 737-800ERX. This is equipped with two CFM International CFM56-7B turbofans, a mission system derived from that developed for the Nimrod MRA4, underwing hardpoints and a weapons bay that is now behind the wing structure. The radar is the Raytheon APS-137 with modifications to enhance reliability. The EO/IR sensor is by Northrop Grumman, as selected for the Nimrod MRA4.

Although presumably inferior to the turboprop P-3C in terms of low level time-on-station, the B737 could cruise much higher, at around 41,000 ft, compared to 29,000 ft for the P-3C. Combined with a 185 km/hr cruise speed advantage, this would allow the sensors of the Boeing MMA to sweep 88 per cent more sea area per hour. It has been claimed that 32 such aircraft, operating from eight forward bases, could replace 51 P-3Cs.

Starting with a 737-800ER off the Renton line, the Boeing option might be expected to cost more (and take longer) to reach full operational capability. However, the company quite rightly argues that the current requirement is so challenging that a P-3C would also need very extensive changes. Boeing places emphasis on reliability, which, combined with speed, will dictate the force structure. The reliability requirement is 79 per cent, but Boeing is aiming for 90, compared to a commercial 737 fleet dispatch reliability of 99. The Boeing MMA would be less expensive to produce, and operating costs would benefit from worldwide spares availability. The company is also offering commercial maintenance support, which would save the US Navy manpower and training costs.

Before leaving the P-3 family and the MMA, it may be noted that the L-3 Communications Procyon, a refurbished and modernised Orion (based on a P-3 drawn from US Navy surplus stocks) was one of the two proposals short-listed for the now-defunct joint Italo-German MPA-R (Maritime Patrol Aircraft-Replacement) programme to supersede the Dassault ATL1. The Procyon concept was to have an airframe with a minimum residual life of 20 000 flight hours, produced by introducing a new-build wing box, a centre fuselage barrel and a horizontal tail, and giving the whole structure the latest anticorrosion treatment. It was to have been powered by AE2100 engines with Smiths Aerospace propellers, or PW150s with eight-blade Hamilton Sundstrand units. It would also have featured a two-man 'glass' cockpit and the IHDS-2000 integrated data-handling system. Maximum endurance was given as 16 hours, a typical patrol speed of 382 km/hr, a high altitude dash of 762 km/hr and a service ceiling of 30,000 ft. Relative to a standard P-3C, the Procyon offered a 30 per cent increase in endurance, 50 per cent improvement in reliability and a 60 per cent reduction in maintenance man-hours per flight hour. The Procyon Quick Reaction would retain the T56 engines. The Procyon (like the Nimrod) failed to make the MMA-Cad shortlist.

The principal alternative to the Procyon in the Italo-German MPA-R programme was a project jointly proposed by Eads Military Aircraft and Alenia Aeronautica, based on the Airbus A320. This 77-tonne MPA320 was to have advanced sensors, tactical data management and communications systems, four extra fuel tanks and an internal weapons bay housing a 4000 kg warload in a forward extension of the wing-body fairing. Illustrations show a chin-mounted EO/ IR turret, a 360-degree radar at the front end of the weapons bay fairing and fuselage hardpoints for two 450 kg air-surface missiles just aft of the wing. The MPA320 would have provided eight hours on station at 1500 km radius and its ferry range was estimated as 7800 km, with a cruise speed of Mach 0.78.

Proposals were made to the two-nation programme office in Koblenz, based on ten MPA320s for Germany and 14 for Italy, with deliveries in 2007/2008. However, the MPA-R programme collapsed in July, due to funding problems and a divergence of planning. Both countries are now considering interim solutions, including the purchase of surplus Dutch P-3Cs (ten available) or French ATL2s (six), or a short Slep for their ATL1s, which can continue until 2015-2017 at best. Italy is said to be reassigning some ATL1 roles to the Lockheed Martin C-130J and the European Helicopters Industries EH 101 helicopter.

Benefiting from experience with the MPA320 study, Eads has projected a less expensive 75.5-tonne MPA319, based on the A319CJ corporate jet, which has provisions for up to six additional centre tanks and a ferry range of over 11,500 km (compared to 7800 km for the MPA320). It could provide over ten hours on station at 1500 km radius. The "weaponisation" concept is different from that of the MPA320, stores being carried in two ventral 'canoes' mounted ahead and aft of the main undercarriage. The forward canoe would typically house three or four Kongsberg NSM anti-ship missiles and the rear canoe four Eurotorp MU90 lightweight torpedoes. The canoes have electrically-powered sliding doors. A 360-degree radar can be retracted into the wing-body fairing to reduce drag whilst in transit.

Both the A320 and A319 would be available with the choice of IAE V2500 or CFM56-series engines. The A319 is felt to have considerable market potential, but Eads would probably need orders for around 20 aircraft to justify launching a full-scale development. Eads claims that, at a typical radius of 2800 km, the MPA319-CJ could provide twice the time-on-station of (for example) an ATL2, allowing a 30 per cent reduction in force structure.

From Russia

The Russian equivalent of the Orion is the 66-tonne Ilyushin Il-38, powered by four Ivchenko AI-20M turboprops. Around 65 were built, including five that were delivered to India in 1977. In 2001 India contracted for its aircraft to be upgraded to Il-38SD standard with a ten-year life extension and the inclusion of the Leninets Sea Dragon mission system, based on the company's Novella developed for the Russian Navy Il-38N upgrade. This programme was placed in jeopardy when two Indian Il-38s collided in mid-air last year. However, Russia provided two surplus aircraft free of charge, and the Il-38SD had its maiden flight in July.

Russia and India also operate the massive (185-tonne) and far more capable Tupolev Tu-142M, powered by four Kuznetsov NK-12MV turboprops. India is having its eight aircraft fitted with the Sea Dragon system developed for the Il-38. Aside from its maritime patrol duties, the upgraded Tu-142M will also serve as a communications link between a ground control and India's new indigenously-developed submarines.

Rising Sun

In late 2001, the Japan Defense Agency selected Kawasaki as prime contractor for the P-X project that is to replace the P-3C domestically. The four-engined P-X is to have extensive commonality with the twin-engined Kawasaki C-X, which is to replace the C-1. The engine for P-X is expected to be the Ishikawajima-Harima F7 high-bypass turbofan, the first experimental version of which was delivered for testing in September 2002. It is estimated that around 350 engines will be required for P-X, implying perhaps 80 aircraft. First flight is scheduled for 2007.

Great Britain

The other new four-jet maritime patrol aircraft is the 105.4-tonne BAE Systems Nimrod MRA4, of which 18 are to be produced for the Royal Air Force by upgrading old MR2s. The MRA4 will have new wings, Rolls-Royce Deutschland BR710 engines and a Boeing mission system. New armament includes the MBDA Storm Shadow cruise missile. The MRA4 programme has been the subject of severe delays and cost overruns, and the first aircraft is now expected to fly around the end of this year, leading to service entry in 2009.